i like what you did what Arcane Blast. i tried out it earlier and had some pretty damn good matches. i would do RtL, Updrate, run forward a bit and do the fire roll, then the fire circle + Arcane Blast for damage and might, then a quick earthquake for more might and a knockdown. then i'd go from there. it was working pretty well.
i'm still trying to decide whether i want cantrips to recharge 20% faster or have them give regen and vigor. i'm thinking maybe the latter since i took cleansing fire out and i'm spec'd for regen to cleanse.
The main reason I don't put updraft in my rotation is because in tPvP it's invaluable for the knockdown to interrupt stomps, rezzes etc.
Honestly if that's the toss up I would always go for Regen and Vigor, this makes you a lot more tanky than having your Cantrips back slightly faster, not to mention the extra boons you get translate into more damage via Bountiful Power.
The only argument to be made here is wether you take Cleansing Wave or Cantrip Mastery, running Ether Renewal provides you with a lot of condition removal, add Dagger 5 and dodge roll in water attunement to that and you got all the individual condition removal you need. I personally opt for the Cleansing Wave trait as it cleans allies too when i swap to water attunement.
Normally I wouldn't pass up Powerful Auras but in some rare cases I take Cleansing Water (if my team lacks proper condition control because we're not running a necro and the other team is for instance).